Q. "I talked to a building product supplier for WALLTITE spray foam, he is suggesting to use 2" or 3" of closed cell-spray foam in the joists areas instead of the batts insulation. He says it will work with outboard rigid insulation. There is a location of a cantilevered floor area with steel beam so I may need to use spray foam to protect the steel beam. It would then be convenient continue to spray in the floor joist cavities and then apply 5" of polyiso outboard of the bottom cantilever floor sheathing."
R-value, the thermal resistance measure of insulation, varies between all insulation products whether they are fiberglass, cellulose, open-cell spray foam insulation or closed-cell sprayed-in foam insulation. Generally speaking the rule of thumb is the higher the R-value, the greater the insulating power. Focusing on spray foam insulation materials, there is a difference between the two main types. According to industry publication, Fine Home Building, the R-value for open-cell spray foam is between R-3.5 – R-3.6 per inch. However, there are open-cell spray foam insulation products actually offer R-3.7 per inch such as Icynene Classic and Icynene Classic Max. The open cell structure of low density foam insulation means the R-value is lower than its closed-cell counterpart. Nevertheless, open-cell spray foam does offer superior and consistent thermal insulation and air sealing properties.
Although spray foam insulation has been in use since the 1940s, primarily for aircraft, for the past 30 years, continual product innovation has seen the increased adoption of spray foam insulation in residential and commercial construction. The rapid growth of sprayed foam insulation in building construction, thanks in part to its immediate and long-term benefits, has allowed the insulation material to sit confidently alongside traditional insulation types in providing thermal comfort for building occupants.
Having a recreational vehicle, see to it that you protect its roof from anything that would otherwise damage it or decrease its lifespan. One of the best maintenance and repair products you need is the best RV roof coating. It can offer you a host of benefits we’ve mentioned above, so it is really necessary for your RV cleaning and maintenance products arsenal. Pick based on those we’ve featured here as well as on certain factors, including your roof material, for the desired results. Did you like this guide? Share it on Facebook today! If you’re looking for more products in RV cleaning and maintenance, then I suggest going for these articles: best RV wash and wax, best RV roof sealants, best RV caulks, best RV wax, best RV roof cleaners and best RV awning cleaners. I do hope you will like them. Happy shopping!
Most closed-cell spray foam is now formed using hydrofluorocarbon (HFC) blowing agents that have high global warming potential, partially or completely offsetting the climate benefits of the energy savings they can offer. In the United States, HFCs are scheduled to be phased out by January, 2021. A few spray foam suppliers have started supplying spray foam blown with hydrofluoroolefin (HFO) blowing agents without this problem as of early 2017. http://youtube.com/watch?v=ggLAUsiuI_o
If your foam pulled away just a little bit, Jamie, and they were able to fix it with just a little bit of touching up, then it wasn't as bad as the house where I saw this problem. As the last photo above shows, it had pulled away significantly from the studs and rafters, and it was all over the house. This was closed cell foam, and interestingly, it didn't pull away from the horizontal framing members, just the vertical and sloped ones. They did some touch up, but that wasn't enough. I don't know how this one ended up getting resolved. I think maybe the contractor came back and sprayed cellulose on top of the foam.
Allison--would be very interested in your take on the GHG issues of foams, which have received lots of smart commentary recently. To highlight a few: architect Jesse Thompson's comments on Tom's Good vs Bad post on Energy Circle, the very thorough piece by Alex Wilson on Green Building Advisor and Michael Anschel's cautionary diatribe on Remodeling. http://kvsprayfoam.com/images/KV-Spray-Foam-insulation-Denver-Colorado.jpg
However, coating asphalt shingles and built-up composition roofs requires more caution. The National Roofing Contractors Association’s (NRCA) director of technical services has stated "The roofing industry is aware of a number of issues that could have negative consequences for field application of coatings over asphalt shingle roof systems. Anyone considering this type of application should be aware of the concerns so they can weigh them against the benefits claimed in coating product promotional materials." http://youtube.com/watch?feature=youtu.be&v=ggLAUsiuI_o
2. I talked to a building product supplier for WALLTITE spray foam, he is suggesting to use 2" or 3" of closed cell spray foam in the joists areas instead of the batts insulation. He says it will work with outboard rigid insulation. There is a location of a cantilevered floor area with steel beam so I may need to use spray foam to protect the steel beam. I would then be convenient continue to spray in the floor joist cavities and then apply 5" of polyiso outboard of the bottom cantilever floor sheathing.
Note: A board foot is defined as a 12" x 12" square at 1" thick. Actual output can be affected by a number of factors including temperature and humidity. The theoretical yield has become an industry standard for identifying certain sizes of two component kits. Theoretical yield calculations are performed in perfect laboratory conditions, without taking into account the loss of blowing agent or the variations in application methods and types.
R-value is the term given to thermal resistance to heat flow. The higher the R-value of an insulation product, the more effective the insulation properties. Spray polyurethane foam comes in a range of densities and cel structure. Low density foams are referred to as Open Cel SPF while higher density foams are referred to as Closed Cel foam. 1.8-2 pound polyurethane foam has the highest R-value of readily available spray foam insulation used in homes and buildings. http://www.youtube.com/embed/ggLAUsiuI_o
If you’re not familiar, spray foam is a type of insulation that expands after you spray. The foam expands and seals, avoiding any type of unnecessary moisture (which can create mold) or encouraging pests to eat through your walls. It protects the lining of your house, and even can protect the heating and cooling of your house during those unbearably cold or hot days.
Get the Power to Seal & Insulate Perfectly in Just 5 Minutes. The Foam it Green Promise: 1>Simpler, Easier, Faster Spray Foam 2>No Special Skills or Know How 3>Professional Results or Better Saves You Time, Money and Hassles. Delivers to your door, ready to use. Just follow the simple instructions. Saves Energy with High R-value Closed Cell Foam. R-Value of 7 in Just 1 Inch. Provides a seamless air barrier in 1 step. This Kit Provides Approx. 602 Square Feet at 1” thickness of cured foam. Class I E-84 Fire-Retardant Foam that meets building code specs. This Anti-Microbial Formula passed the stringent ASTM G-21 test for preventing mold growth on the surface of the foam. Includes everything you need to complete your project. Weighs 120 lbs, including steel canisters pressured with nitrogen. Orders with multiple kits on it may ship via LTL instead of UPS. The LTL carrier calls to arrange a convenient delivery time. Usually Ships Same Business Day. See Manufacturer for returns and warranty policy.
What more is that we also think it is one of the most durable among liquid roof coatings on the market. It can last for several years, working continuously in protecting your roof from outside elements, such as dust, leaves, twigs and debris that would otherwise damage your roof. When it happens, your roof might have leaks and cause discomfort inside your RV.
The local foam installer that I used here in Hilton Head told me he looked for some peeling back of the foam. This was ensuring that it was at the perfect temperature which helped them maximize their yield (profit). I have open cell foam and it pulled away a little, and did so immediately (within minutes). They went back after they were done to any spots that pulled away too much and filled them with the touch up kit; they were looking for the top edge to roll just a little bit.
With constant exposure to heat, cold, UV radiation, rain, snow, hail, high winds and possible mechanical damage, a roof can be the most vulnerable component of a building’s exterior. However, a roof’s long-term performance can be enhanced — and major roofing problems avoided — with correct design, quality materials, proper installation and workmanship, and comprehensive care.
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